sinister Definition

sinister
adj

1. Suggesting or threatening evil or danger; malign.

Thesaurus: evil, corrupt, perverse, malevolent, ominous, threatening, baneful, pernicious, deleterious; Antonym: innocent.
2. Inauspicious; ominous.
3. heraldry.
On the left side of the shield from the bearer's point of view, as opposed to that of the observer. Compare dexter.

Derivative: sinisterly
adverb

Etymology: 14c: Latin, meaning ‘left', believed by the Romans to be the unlucky side.